Green Laser Inter-Satellite Link Planning in Satellite Optical Networks: Trade off Battery Lifetime and Network Throughput Using Numerical Quantization

In satellite optical networks (SONs), laser inter-satellite links (LISLs) are energy hungry to drive pointing, acquisition, and tracking systems and laser devices to maintain fine link pointing and provide communication services. Rechargeable batteries are the sole energy support for satellites in the eclipse region, and unrestrained use of batteries may accelerate battery aging and shorten the satellite operation period. Real-time sleep/activate control on demand is not applicable to reduce the energy consumption of LISLs because waiting for link pointing delay is intolerable for most traffic requests, and aperiodically changing LISLs’ working states may affect the routing reliability in SONs. For the above problem, this paper proposes green LISL planning (GreenLP) to periodically switch LISLs’ working states to prolong the battery lifetime. Considering the possible degradation of network throughput by sleeping LISLs, this paper models GreenLP as a double-objective optimization problem from the perspective of topology design, and two topology features are expanded based on traffic prediction to numerically quantify LISLs’ potential importance. Simulation results indicate that, compared with existing schemes, GreenLP reduces battery lifetime consumption by 8.93% and the probability of request blocking by 5.65%. Numerical analysis shows that the expanded node betweenness centrality has the effectiveness and universality to quantify LISLs’ potential importance on network throughput.